i read an article about datacolumn.expression property here [URL]. this is really great. but i was just wondering, for my case i want to use my custom function to use in the expression. basically, on my datatable i added an unbound column AGE. when i display records, i just want the age textbox to be populated with the computation of the person's age based on birthdate.
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I am trying to write following expression on a datacolumn. But it results in error:Replicate('*', nLevel) + NameWhere: Replicate() is a user defined function (in a module). nLevel and Name are two other columns in same data table.
View 3 RepliesIs there a way to change when an expression in a datacolumn is evaluated?
I'm trying to make a simple total function which sums the values of a particular column in a data grid. Normally the expression is evaluated when I leave from the datagridview, but I wish it to be evaluated when the row is changed.
datacolumn expression subtracting dates and taking to datagridview
View 1 RepliesI am trying to build a filter string for my DataView, but I have run into a problem. My underlying DataTable contains values that are formatted when displayed in my DataGridView.For example, if the DataColumn contains 1.52 and the DataGridViewColumn.DefaultCellStyle.Format = "n0" then 2 is displayed.So the user sees 2, then sets the DataView.RowFilter = "DataColumn = 2", and no DataRows are returned. Is there a way to format the DataColumn in the RowFilter string? For example, DataView.RowFilter = "FORMAT(DataColumn, "n0") IN (2, 4)". This filter string should return 3 rows. If not, can LINQ do this?
View 5 RepliesI have a DataTable with two DateTime columns: "start_time" and "end_time".Now, I want to add a third column that calculates the difference between the two DateTimes. But I can't seem to figure out how. I've tried to set the .Expression-value to "start_time - end_time", but it says that "-"-operator is not allowed on DateTime.
View 4 RepliesDuring a code review I looked at set of repository classes (in vb.net). I am used to seeing these repository classes full of functions that return collections (among other things) of your domain objects. However, this repository had 1 public property and 1 private variable that looked something like this:
Private _item as Collection (of Customer)
Public Item as Collection (of Customer)
Get...
Set...
In the "Get", there is code that gets a the Customers from the DAL and loads it in the private _item. What would the benefits be in using a property (customerRepository.Item) instead of plain old function (customerRepository.GetAllCustomers)? The "Property" way looks odd to me but odd doesn't always mean wrong.
I have a DataColumn and call the MaxLength Property on it to get the length of data that can go into a field ... but it always returns -1 (yes even on a string field).
View 8 RepliesI have added a column to a Datatable called CallsPerDay which is there to tell me how many telephone calls have been made on a particular day or days.Is there a datacolumn.expression which will allow me to Filter on the day, count the rows and then populate this added column with the result.
View 1 RepliesI am using Flee to build a formula builder. It works great but the only problem I'm facing is that Flee doesn't understand Generic Methods I guess. I have a function called IIf declared in the expression context I'm using. [code]How can I work around this. I mean cannot , in sense, write all possible overloads of the function of all .net primitive types. What approach should I take.
View 1 RepliesI have an ASPX Custom Control which is supposed to load it's properties into an internal collection (defined with PersistenceMode.InnerProperty). Here's the ASPX
<cc:CustomControl runat="server">
<Queries>
<cc:QueryTypeOne ... />
[code]...
I have a problem with a property on a custom property of a class. Here is the actual code for the inherited form
Public Class Form : Inherits System.Windows.Forms.Form
Private _Active_Application As Custom.Classes.Active_Application = New Custom.Classes.Active_Application
<System.ComponentModel.EditorBrowsable(ComponentModel.EditorBrowsableState.Always)> _
Public Property Active_Application() As Custom.Active_Application
[code]....
but when i use a separate class to inherit the above class this property ('Active_Application', not Custom.Classes.Active_Applicaton) is disabled.
I have a function which creates a different type of expression depending on the value of the variable passed in.[code]...
View 1 RepliesI want to make sure using the custom expression validator that no ' or " can be used i tryed using [^"'] but whenever i put normal letters it doesnt work either.
View 1 RepliesI just want to ask if it is possible to create a function that accepts an expression into its arguments. Just like what IIF do. Ex: Dim strResponse as String = IIF(Msgbox("Select Yes or No", vbYesNo) = vbYes, "Yes", "No") I forgot the code, but its the thought that counts.
View 1 Replies1.print the cars which are fast moving cars.
i have written this code but it shows message Cannot have aggregate function in expression[code]...
Should I be concerned about the performance of the Compile method here?[code]...
The reason I want the lambda expression is because I want that function to be able to get all the way through LINQ-to-SQL to be converted to SQL. The reason I want the direct version is because I have other code that I want to validate individual serial numbers before submitting changes. And I fear that GetValidSerialNumbers.Contains(serialNumber) will execute a more-complex-than-necesssary query.
i want to set a complex column expression truncate(cdbl(Today()-date2)/30)*(parent(parentchild).field1/parent(parentchild(filed2)))but truncate function is not available !
View 12 RepliesHaving problem understanding Delegate error. Error says expression expected, How do I fix?Here is the offending line (#259)....
mylist.ForEach(Delegate Function(P As linkItem) As System.Char[] )
Here is the entire code.
<script language="VB" runat="server">
Function sectionTitle(ByRef f As String)
'Open a file for reading
[code]....
I need to execute scripted text formulas. I believe that in VB 6 and/or VBA there was a method EVAL() that did the job, eg: [Code] As it seems, such a method does not exist in VB.NET. [url] The method works fine but due to its comprehensive layout its not that fast (as i need to call it myriad of times) Does anyone have a SIMPLE, FAST, straight forward math expression method? Or anyone knows how to use the old EVAL method in VB.NET?
View 10 RepliesHow can I shift the GET-implementation of a Class property to a / using a custom attribute? (I've added instantation vars (classname, propertyname) to the attribute, however I'd rather have these automatically fetched ofcourse.)
Public Class CustomClass
<CustomAttributeClass(ClassName:="CustomClass", PropertyName = "SomeProperty")> _
Public Property SomeProperty() as String
Get() as String
[code]....
I am using Expresion Blend 3 and created a new user control in my project. I want a storyboard to run if a custom property of that user control is triggered like with the ones shown here in the list..
I learnt you need a dependency property, but my understanding there is limited. Here's the basic code I set up with property "IsAwesome" as an example[code]...
I have created a custom class, which contains a panel and a label on it. I added to this class a pcaption property, which holds the label text. This property is browsable and I can change its value.But when I drag the custom control to the form and change the pcaption property, it has no effect. Even the <Defaultvalue> has no effect. Why?
Here is the class code:
Imports System.ComponentModel
Public Class mypanel
Inherits Windows.Forms.Panel
Private panelcaption As String
[code]....
Color values are unimportant, you can change it.
I created a new DataGridViewColumn type called DataGridViewGradeColumn.
Public Class DataGridViewGradeColumn
Inherits DataGridViewTextBoxColumn
Public Property AssignmentName As String
[code].....
I have two forms, say Form1, Form2
Form1 has one textbox and one button, Btn1 when clicked, it opens Form2 as dialog.
Form2 has one textbox and one button too.
First I click on Btn1 to open Form2 as dialog. And when I click on Btn2 on Form2, I want the text in the Textbox2 to be copied to TextBox1. I know it could be done by Public Property Get, Set but I am stuck.
this is the code for my property
Dim _playernumber As Integer
Property Player() As Integer
Get
[code].....
I am developing a custom control with VB9, and I want to add a Property Name TextFileName this property need to use OpenFileDialog, which type I can use when I define this property?
for example another property I use is EnterFocusColor and its type is System.Drawing.Color so when the user select the property it opens the ColorSelectionDialog Hany M. El Tarhony
I'm trying to add validation to one of my class properties:[code]The value for the golfer's handicap comes from a oombo box on the form. Even if I have nothing set for this property at runtime, my validation doesn't work. I tried putting the If statement under Get instead of Set, and tried mHandicap = value after an Else in the If statement, but nothing seems to work. I'm working in the dark here and can't find anything suitable online. I was hoping to not go down the path of ReadOnly or WriteOnly properties as I'm not at that stage yet, but does this make a difference for my purposes here? Can anyone guide me as to what I'd need to do from this point? If I've got it right, you can add validation in the class and this means that you then don't need to repeat this validation in the form??
View 3 RepliesI have created a CustonControl (NOT a usercontrol) and defined a DependencyProperty as following
[code]...
I have created a little demo application which is able to create a meeting request by using the Exchange WebService (EWS). I would also like to add some custom properties to this item but up to now I have only found examples which use the Exchange Managed API, which I won't use. There must be a way to create these properties by only using EWS... Does anybody know how and can provide a little code example?
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